HttpServer MBean.
This Model MBean class provides the mapping for HttpServer
management methods. It also registers itself as a membership
listener of the HttpServer, so it can create and destroy MBean
wrappers for listeners and contexts.

defineManagedResource

Define the Managed Resource.
This method is called the first time setManagedResource is
called with a non-null object. It should be implemented by a
derived ModelMBean to define the attributes and operations
after an initial object has been set.